Friction transmission



Feb. 9, 1932..`

J. EHRLICH ET AL FRICTION TRANSMISSION Filed July 21, 1930 4Sheets-Sheet l Feb., 9 1932 1 EHRLKCH ETAL '1,844,464

FRICTION TRANSMISSION Filed July 2l, 1950 4 Sheets-Sheet 2 Wdh.. 9,1932. J. EHRLICH ET AL 1,844,464

FRICTION TRANSMISSION Filed July 2l, 1950 4 Sheets-Sheet 3 5.! I ll .Illll A www@ FEB. 9g, 1932. J. EHRLicH ET AL FRicToN TRANSMISSION FiledJuly 2l, 1930 4 Sheets-Sheet 4 Patented heb. 9, lg3d il'lUUE lEUEtLfCH,OIF DIETE-01T, AND JHN 0. ALMEN, 0F ROYAL OAK, 'MICBIGAN, S-f

lttlllll TO GENERAL MUTRS RESEARCH CORPORATION, 0F DETROIT, MICHIGAN,

A CURtDORATN COF DELAWARE .TRJICTON '.lft-ANSMISSIUN .Application filedJuly 2l, 11.930.

'l` he invention forvlhich the protection of a patent is hereby soughtis fully disclosed but not claimed in an application for friction'transmission Ser. No, 414,899, `filed December i8, i929, by JacobEhrlich.

'lhe invention is illustrated and described as embodied in atransmission, of the kind disclosed in said application, which comprisestivo disk-like members attached to an assumed driven shaft and anintermediate double surfaced disk-like member connected to an assumeddriving shaft in axial alineinent with the first named shaft. 'lheassumed driving and driven shafts may, howover, be reversed in function.The driving and driven disk-like members, hereinafter designated races,have opposed toric surfaces.l hereinafter called race ways, engaged bytvvo series of relatively balanced idler rollers having spheroidaltraction surfaces. rlorque is, therefore., transmitted from drivingshaft to driven shaft by a double surfaced driving race,-thel equivalentof two rigidly connected iaces,-'tvvo driven races and two parallelseries of idler transmission rollers.

'll'o change the speed ratio it is necessary to change the angle betweenthe axis con mon to the driving and driven races (the main axis) and theaxes of the idler rollers in a plane substantially including both. 'lhemovement to effect this change is hereinafter designated a tiltingmovement ortilt. lo do this directly it would be necessary to compel thetraction surfaces of the idler rollers to slide on the race Ways. rlhiswould require a very considerable force, as relatively high pressuresare needed. to obtain traction when th'e load is heavy, and, ifpossible, ivould result in Wear. ment disclosed the tilting movement isobtained indirectly by rocking the rollers in a plane transverse of theaxis of the driving and driven races substantially around an axisjoining their points of contact with the race ivays; whereupon theforces inherent in 'the rotating disks and rollers cause the rollers toassume a new speed ratio relation. Said rocking movement requires theapplication of very little force and is hereinafter designated theinclining movement.

ln the embodi- Serial No. 469,396.

'llhe idler rollers are inclined by means of a train of speed ratiocontrol elements extending therefrom to a main control lever Which canbe locked to and released from a segment by a friction locking devicethus permitting infinite gradations of locked position Within the rangepermitted.

Any inclining of the idler rollers as dcscrihed to edect indirectlytilting, or new speed ratio relation, inclines the roller axes withrespect to planes which include nor# mally the main axis and the rollercenters and imparts to the rollers a tendency to trace spiral paths onthe races,-a tendency that would continue unless counteracted. Thereforein accordance With this invention a return device is utilized in theform of parallel surfaces oblique to a radial plane including the rollercenter and the main axis on each rollerfsupporting trunnion, Which afford a tilting axis slightly inclined With respect to a plane normal tothe main axis in a plane normal to the axis of rotation of the rollerand, in response to the tilting movement, effects restoration of eachroller axis into said plane that normally includes the main axis androller center, thus avoiding the necessity of the operators trying tostop the spiraling of the rollers by manipulating the main controllever.

The accompanying drawings, in Which like reference characters indicatelike parts throughout the several views, illustrate one Specificembodiment of the invention. ln said drawings:

lFig. l is a longitudinal section substani tially in a plane indicatedby the line l-l of F ig. 3;

Fig. Zis a longitudinal section, substantially in a plane. at rightangles to the plane of liig. l. taken on line 2--2 of Fig. 3; butomitting intermediate idler transmission rollers;

Fig. 3 is a transverse section substantially on line 3 3 ofrFig. l;

Fig. l is a detail face view of one of the intermediate idlertransmission rollers with its trunnion and associated parts;

Fig. 5 is a detail showing a ratio control lever actuating ring and oneof the idler will transmission roller ratio control levers enga ed; Y

ig. 6 is a plan of one of the idler transmission roller ratio' controllevers;

Figs. 7 and 8 are details of the idler transmissionI roller trunnionblocks, and

Figs. 9 and 10 are a face view and section, respectively, of a couplingring in the train of ratio vcontrol elements.

Referring to Figs. 1 and 2: Numeral 10 indicates the main body'of a.transmission housing having opposite open lends covered by closures 11and 12 removably secured as lby bolts13. Conventional means of fixingthe housing to a supporting base or frame are vshown as flanges 14having bolt holes 14a.

The housing is equipped with bearings 15 and 16, shown as ofanti-friction type, disposed centrally in closures 11 and 12. In theillustrated construction the bearing 15 in clovsure 11 receives thedelivery end of a racecarryin shaft herein considered as the drivingshaft; bearing 16 receives the race-carrying driven shaft which also hasone end recelved in a socket in the driving shaft. Closure 11 istherefore at the power input end of the transmission housing and closure12 at the power output end. The alined and coinci# dental axes of races,driving and driven shafts constitute the main axis of the transmission.

The transmission shafting essential to the invention comprises a shaft18, deemed to be the drivin shaft, which may be rotated by any suitab eprime mover, and a. shaft 19, deemed to be the driven shaft, in axialalinement with the driving shaft. One end of the driven shaft (as shownat the left in Figs. 1 and 2) may have a slightly reduced end 20journaled( in a socket 21 formed in the contiguous end of the drivingshaft illustrated as enlarged at 22, said enlarged end being supportedpreferably by rollers within said bearing 15 in the power input end ofthe housing; an anti-frictlon bearing for reduced end 20 of the drivenshaft may be provided wit-hin socket 21 by rollers 21a, and a removableannulus 24 may be boltedto the closure 11 for the purpose of aiding toposition the rollers ofbea-ring 15 and to retain lubricant. In a centralopening in output end closure 12, bearing 16, shown as a ball bearing,is asembled within a flanged bearing holder 16a bolted to the closure at16h. The races of the ball bearing 16 may be positioned axially `withrespect to the shaft 19 and locked against a shoulder thereon bythrustbushing 16o controlled by a lock nut 16d threaded on the shaft. Thisbearing construction allows shaft 19 and the bearing races, thuslongitudinally xed thereto, to slide axially a limited ex-l tent Withinthe flanged holder 16a and hence, also, to move axially with respect'tothe housingDand jparts fixed to it.

riving shaft 18 imparts driving torque to about the axis of driven shaft19. Torque is transmitting from disc o1' race 32 to discs or Iraces 30and 31, mounted to rotate with shaft 19, by intermediate transmissionrollers 40 and 41. lVith discs or races and rollers positioned asillustrated, driving and driven shafts will rotate in oppositedirections at the same speed.

In Figs. 1 and 3 a transverse support 26 is shown rigidlyunited to thehousing by means of which and parts rigidly connected to it the rollers40 and 41 are positioned and maintained with their center points insubstantially fixed relation with respect to the main axis and housing.Support 26 is shown as a spider having equally spaced rad'ating longarms 28 the end of at least one of which is secured to housing l0 as bybolts 30. Short radiating arms 29, rigid with the spider, are spacedequally between the long arms. Said 'short arms 29 serve to positionintermediate transmission rollers 40 in a manner to be hereafterdescribed.

' The spider 26 is welded to or otherwise made rigid with a long hub ortorque tube 27 near one end-the right hand end as shown in Fig. 1.Pinned to or otherwise made rigid with the torque tube near its oppositeend is a second spider 26a provided with short radiating arms 29aequally spaced angularly. Arms 29a serve to position intermediatetransmission rollers 41. The positioning arms are shown as three innumber on each spider, equally spaced angularly, with the correspondingarms of each spider in the samev balanced with respect to one another.Bearing rollers 17 are interposed between torque tube 27 and shaft 19adjacent spider 26; other bearing rollers 42 are interposed between thetorque tube and shaft adjacent spider 26a. Shaft. 19 may thereforerotate freely within the torque tube.

A spacing tube 48, constituting also an element of speed ratio controlmechanism, is interposed between saidbearing rollers 17 and 42. Saidrollers are spaced from the end races l30 and 31 by short spacing tubeswhich in the illustrated form of the invention are tubular hubs 49 ofoil spray distributors described in detail in said prior application.Suiiicient spacing is providedv between bearing rollers and spacingtubes 49 to permit slight movement of approach, one toward the other, ofsaid spacing tubes. The length of torque tube 27 is such as to allowraces 3() and 31 slight movement of approach one toward another. Spacingand control tube 48 is capable of oscillating within torque tube 27 forthe purpose of transmitting control movement tointermediate transmissionrollers 41 ina manner to be described.

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petasse i i two driven races 30 and 3l are connected to driven shalt i9in such manner as to compel said sbaitt to rotate with them but topermit relative arialk movement ot' one race toward the other forpurposes ot adjustment as will presently appear. Double race waydrivingv race 32, interposed between the driven races, is rotatablefreely around the anis oit shalt i9, being journaled, as illustrated, ontorque tube 27. @pposed torio grooves 33 and .3st, ot similardimensions, occur in the opposing faces oi races 30 and 32,respectively; similar grooves 35 and 36 occur in the opposing `laces otraces 3l and 32, respectively. Said torio grooves function as bearing`and traction surfaces or race ways tor said two series ot intermediatetransmission rollers 40 and 4l which have spheroidal traction surtacesand are positioned by said shorter radial arms 29 and 29a ot the spiders26 and 26a so as to bear .on the .torio surfaces 33, 3st, 35 and 36.lntermediate race 32 is secured to driving shaft 18 by means ot theconoidal Harige or spider 43 and the rigid connecting member fla, whichmay be a ing pins a5 serve as driving connections be-y tween member llland race 32. Said member lll may be welded or otherwise xed to spiderd3, and the latter may be bolted, as at 46, to a tlange l? on the torquedelivering enlarged end 22 ot the driving shaft.

Race 3l may be keyed to shaft l9 as shown in llig. l and prevented trommoving thereon toward the end by a collar 50, preferably adjustablysecured to the shatt. Race is tree on Shaft 19 except as it is compelledto move axially on it and rotate with it by means herein called springand torque loading devices whereby a predetermined axial thrust isapplied at all times and a thrust proportional to the torque deliveredis automatically applied between shaft 19 and race 30, tending to causeraces 30 and 3l to approach one another and the intermediate drivingrace 32. The specific form of these devices is not material to the meansclaimed herein. Theyare described in detail in said prior application.

lntermediate transmission rollers 40 and all, which have been stated tobe positioned between races 30 and 32, and 3l and 32, re-

spectively, by spider arms 29 and 29a, are of annular 'term havingspheroidal peripheries curved on a radius equal to or somewhat less thanthe radius ot the curve ot the torio raceu'ays in a radial planeincluding the axis oit the races. rlhe inner periphery otm each annularroller preferably engages balls interposed between it and an annularrace 616.

lln order to vary the speed ratio oft-he Idriving and rdriven shat'ts,intermediate transmission rollers 40 and Ill must be caused l, mission.lln so tilting, it the periphery ot the intermediate rollers are causedto engage the central driving race 32 on circular paths nearer the mainaxis than paths where they engage the driven races 30 and 3l, the speedot the driven shaft obviously will be lower than the l: l speed ratioobtained when the peripheries ot the intermediate rollers engage thedriving and driven races at paths equidistant from said axis, as shownin the drawings. Conversely, ifvthe paths of engagement With the drivingrace are farther from said axis than the paths of engagement with thedriven races. the speed of the driven shaft will be greater than said l:l ratio.

To enable the speed ratio to be varied bearing rings 66 are mounted onthe arms 29 and 29a by means of compound trunnion elements now to bedescribed: f

Snugly fitted Within each bearing ring 66 are two diametrically opposedtrunnion blocks 67. These trunnion blocks 67 arelof parti-cylindricalcontour,-as it' sliced from a cylinder or planes parallel with the axisand each other. A block locating member 68 is rigid with each trunnionblock at its inner end` projecting beyond the curved surface asillustrated. They are shown in the drawings as flat discs welded to theends of the blocks. When assembled within the bearing rinl 66, members68 serve to position blocks 67 with their inner ends substantially flushwith the inner face of the bearin ring. The opposite end of each block67 is er'fed as at 69 to receive a second locatin' melnber, shown in theform of a flat ring l70 having opposed internal segments 7l bounded bvstraight parallel edges (chords of a circle) tali seated 'in the kers ofopposite trunnion blocks With its inner face in contact with the bearingring 66,--thereby asslsting to hold thetwo blocks of a trunnion inproper relative position with respect to each otherv and to the bearingring.

Each of the intermediate transmission roll* ers 40 and 41, with itsbearingand trunnion blocks, is fitted over a trunnion element consistingof a speed ratio control lever 72 of U-form having spaced parallel limbs73 and 74 of unequal length of which 74 is the longersaid spider armnear its outer end by pin 76.

pposite faces of lever 72 transverse of the spider-embracing surfacesare ,parallel and oblique to a plane including the fulcrum axis t ra(axis of pin 76) cutting the lever lengthwise,-'a plane which, in the1:1 ratio condition shown in the drawings, is a' radial plane includingthe main axis and axis of rotation ofthe intermediate transmissionroller. The Obliquity of said opposite faces may be approximately 5(measured in a plane perpendicular to the plane that includes the mainaxis and the roller center and parallel'to'the main axis,) in theexemplary embodiment as indicated in detail Fig. 4. Opposite trunnionblocks 67 have their at surfaces bearing lengthwise on said obliquefaces of lever 72; and to provide area of bearing surfaces adequate toprevent clocking of the .trunnion blocks each limb of the lever arm 72may have outward-bulging flanges 77 having surfaces co-planar with andconstituting 'part of said oblique bearing faces. rlhus provision ismade for tilting each of the rollers 40 and 41 about an axis which isinclined at an angle of about 85 to a radial plane including the mainaxisand roller center in a plane normal. to the axis of rotation of theroller The sense of inclination of the axis about which a roller maytilt is from the-roller center toward that quadrant of the driving racewhich is approaching theY point of contact between race and roller asshown in Fig. 4. Inclination of the axis of the roller as described inthe said tangent plane by the means described provides for returningLthe roller axis into a radial plane in response to the tilting movementof the rollers initiated by inclining the axis out of the radial plane;this constitutes the return device referred to hereinbefore. From thedisposition of each transmission roller and the elements constitutingitstrunnion and connection to the spider arm that positions it,` asdescribed, it will be apparent that a rockingl or inclining movementimparted to -ratio control lever 72 in a plane normal to the mainaxiswill forcibly incline the roller similarly, that is, will incline theaxis of rotation so that if extended it -will pass to one side of themain axis instead of intersecting it; and also that this inclination maybe imparted by the application of very little force since therollerpivots substantially on its points of surface contact with the oppositetorio race ways in races 30 and A32, vor 31 and 32, as the case may be.The

roller, however, is free to tilt about an axis slightly inclined withrespect to the perpendicular to the plane that includes the main Vaxisand the center of the roller, i. e., its axis of rotation may freelyturn so as to assume positions at various angles to the main axis,-'-trunnion blocks 67 then rotating on and in the planes of the obliquefaces of the p'articular ratio control lever 7 2.

The rocking or inclining movement referred to is designed to be impartedto the intermediate transmission rollers manually- The tilting movementreferred to follows The oblique axis on which the rollers tiltautomatically checks the tilting movement,

restoring the rollers in their newly assumedl speed ratio position tothe normal position in which the axis of rotation intersects the'main`axis, which is necessary in order that the inherent forces which.control the tilting of the rollers may continue in equilibrlum.

The rocking movements of ratio control levers 72 about the pins 76 inspider-arms 29,A 29a, to effect inclination of intermediate transmissionrollers 40 and 41 in planes transverse of the mainaxis are imarted by amain control lever 102, shown in ig. 3, which is adapted to operate inunison two trains oflink and lever control mechanisms extending inparallel from the main lever tothe two series of ratio control levers72, which control, respectively, the twoseries of intermediatetransmission'rollers 40 and 41. By operating said lever 102 alltransmission rollers, herefore, are urged to incline simultaneousy fEach of the two trains of link and lever mechanisms referred to by whichthe lever arms 72 are rocked for the purpose of inclining theintermediate transmission rollers 40 and 41 will be traced backwardftothe main operating leverdcommon to both trains.

Considering first the train for inclining the rollers 40 illustrated atthe right of Figs. 1 and 2'and in Fig. 3: v

A rin -like actuating member 80 (Figs. 1, 2 and 5. hereinbeforementioned, having a lurality of radiating lugs 81-three in numer ifthere are three rollers in the series as illustrated-is sleevedlover thetorquer tube 27 close to and on the power output side of spider 26 asillustrated in Figs. 1 and 2. The orifice through ring-like member 8O issubstantially larger in diameter than that portion of the torque tubelover which it is sleeved. Lugs 8l of the ring-like member 80 haveconvexlxr curved edges and engage Withnthe described notches 75 of speedratio control levers 72. In the normal relative positions of ring and-speed ratio levers 72', room is provided for movement of ring lug 81lengthwise of lever 72. The ring 80 is also provided with diametricallyspaced lugs 82 jutting from the face removed from contact with spider 26in a direction parallel with the axis.

Referring to Figs. 1, 2, 5, 9 and 10: Lugs 82 0n actuating ring 80engage corresponding diametrical grooves 83 formed in a float estranea30 in an internal groove 9'? ol: the coupling ring, entend into slots90a in actual ring 80. 'lhe springs are disposed at torque applied toring 841 is transmitl ted edgervise ot the springs to ring 30.

'i apart but 90o from springs 85. Springs 89 clamped at one end inexternal notches 90 lorrned in coupling ring S-l, and at the other endin notches 91 in control ring 88. Springs 99 pass through openings 92 inspider 2,0

2 and 3) `which allow rotative Inovenient oit the parts to which saidsprings are secured suhicient to edect control. lllates 93 secured tocoupling ring 84@ by bolts 85a serve as clamps "for springs 89 and alsoproject through the openings 92 into notches 91 of control ring 98. Saidplates are not essential but itunction in the saine manner as saidconcting lugs and notches 82 and 83 on rings and 3d, respectively, tohold the control ring and coupling ring in the same angular relation incase springs 89 should give way. l lilpring pressed pins 94a are seatedin holes di lled into that lace ot coupling ring 811 `rvlnich isadjacent to actuating ring 30. The coupling ring is held against:movement ayvay liront the spider by the anchorage ot springs to controlring 89, which bears against the spider on the opposite side.; Springpressed pins ella 'lunction to press, yieldingly, ring 90 against theadjacent race ot spider 20 to dampen any vibration that may be set up insaid ring 90 or parts movable by or r-vith it. D

vvill be perceived that rotation ot control ring 99 vvill rotatecoupling ring 841 by means ol' spring and plate connections 89 and 93;and that rotation oit coupling ring 34: will rotate actuating ring 80 bymeans pl its spring, lug and notch connections Which, 1n turn., vvillimpart rocking or inclining movement to ratioA control levers 12, actingto incline rollers L10 in planes transverse oli the main anis. 1t Tvillalso be perceived that springs 95 and 99, respectively arranged ondiameters separated 90, supplemented byplates 93 engaging notches 91 onone oit said diameters, and by lugs 92 engaging notches 83 on the other,enable actuating ring to hoat, or become laterally displaced vvithrespect to control ring 88 and the main axis Withput disturbing thecapability ofthe control ring to rotate said actuating ring. rl'he partsdescribed lunction as a so-called @ldhamcoupling; but the parts of thecoupling illustrated are spring biased to a normal concentric positionwith respect to the main anis by the ilat springs, which also transmittorque. Control ring 89 has an arm 9d rigid with it. 'lhe end ot arm 941is pivoted at 95 to an equalizer bar 96 (Figs. 1 and 3) Said equalizerbar is pivoted by pin 97 between the limbs oi the forked end 98 ot' rodor link 99 which passes through a suitably packed opening 100 in thehousing 10, and is joined at 101 to said main control lever 102 ulcrumedat 103 on a support 104 secured to the exterior ot the housing. Maincontrol lever is held in any adjusted position by means of a `frictionlock 115 engaging with a segment 105..

'lracing now the link and lever train from the other series ofintermediate transmission rollers, 41, to the main control lever 102, itwill be seen upon reference to the left hand portions of Figs. 1 and 2that another Boating actuating ring 80 having lugs 81 engages otherspeed ratio controlling levers 72 for said series of rollers Z1 1, andthat another floating coupling ring 8l is connected to said ring 80 andto a secondary control ring 106 by tlat springs and couplings identicalwith those described in the parallel transmission tor controllingrollers 110. Spider 29a is pertorated as is spider 29 to permit thepassage or' springs 99. lExcept lor their reversed. position the controlelements for rollers 41 are thus far the same as tor rollers l0.Secondary control ring 106 is pinned to spacing tube 18 by pins 107,said pins passing through an ornice 108 `formed in torque tube 27 andhub ot spider 29a, said orifice being of such size and form .as topermit the needful rotary movement ol' the control ring to occur. Asecond pin or pins 109 passing through another suitable opening 110 intorque tube 27 connects tube 18 to another or primary control ring 111to which an arm 112 is rigidly attached. 'llhe outer end of arm 112 ispivoted at 113 to equalizingbar 96 at the end opposite to that to whicharm 94 is pivoted. Thus pin 97 by which thev equalizing bar is attachedto rod 99 lies between theA pivotal connections thereto of arms 94 and112; and

the connections are such that the ratio of length of arm 94 to length ofarm 112, measured trom the main axis, is the same as the ratio oi lengthof the short arm of the equalizing bar to itslong armi-that is, as thedistance fromV axis of pin 95 to that of pin 97 is to the distance fromaxis of pin 113 to the axis ol' pin 97. ln Figs. 1 and 3 it will be seenthat lever 112, as well as equalizer bar 96, is embraced by the limbs offork 98,--also that lever arm 112 is provided with a perloration 114suiiiciently large to allow :free passage of pin 97 and permit slightrelative angular movement of arm 112 with respect to arm 94. The orificein the end of lever arm 112 also is made a little larger than the pin113 which engages in it in order to'compensate lor the di'erent arcs ofmovement of the connected lever arm and e ualizer bar. Acurved leafspring 96a secure within the fork 98 of rod 99 bears frictionally on theequalizer bar in such a manner asto bias they equalizer bar toward aposition in which the axis of the pins 95, 97 and 113 and th main axislie in the same radial plane.

Maincontrol lever 102, in the illustrated i embodiment, is designedto-be operated by i. of the locking device is not a part of thisinvention and is fully described in said' prior application.

Lubrication may be effected by a forced circulation, the oil owing intooil tube 130 which discharges between torque tube 27 and spacing tube 48whence it distributes through suitable grooves, spaces and orifices toparts needing lubrication.

Operation It is desirable to have the prime'mover (not shown) runninguniformly at its most economical rate of speed and to vary the outputspeed by changing the transmission'ratio.

Assuming torque to have been applied to shaft 18, as by an internalcombustion engine,

central driving race 32 will be rotated with shaftrlS at the same speed.Rotation will be i imparted by the central driving race to the twodriven races and -31, thru the two series of intermediate idler rollersand 41 acting in parallel. As shaft 19 must rotate with races 30 and 31it rotates in a sense opposite to that of driving shaft 18.`

The intermediate idler transmission rollers are illustrated in aposition in which `continuations of their axes of rotation intersect andare perpendicular to the main transmission axis extending longitudinallythru the centers of driving and driven shafts and races. Consequentlyall the points or lines of contact between'rollers and races areequidistant from the main axis and the speed ratio of driving to drivenshaft is 1: 1. h'Assuming that driving shaft and driving race rotateclockwise (viewed from the left of Fig. 1) driven races and driven shaftof course will rotate counter clockwise viewed from the same observationpoint. In order to increase the speed of driven shaft (output speed)with respect to that of the driving shaft it will be necessary to tiltthe rollers 40 and 41 in planes that include their axes of rotationandthe main axis in such directionsv that their peripheries will contactwith driving'race 32 farther from its center and with movement for thepurpose of imparting in-i creased speed to the driven shaft with respectto the speed of the driving shaft, main control lever 102 should bemoved downward from its position shown in Fig. 3. Downward movement ofmain lever 102 pushes rod or link 99 downward rocking control rings 88and 111 counter clockwise (as viewed from the left-of ligs. land 2), andalso the entire control train extending from said control rings to andincluding the actuating rings 80 of both series of intermediate idlerrollers. Lugs 81 of the actuating rings, engaging ratio control leversas described, rock these levers on pins 7 6 in a clockwise directionand'consequently rock or incline all of the rollers of both series in aclockwise direction as indicated by the arrows adjacent1 rollers 40`inFig. 3 thus inclining or bringing the roller axes of rotation into aposition where tley y race will be expanding spirals and those on thedriven races contracting spirals, resultin in tilting the rollers in thesenses indicate by the arrows adjacent ,the rollers in Eig. 1.

The pitch of' said spirals will obviously vary in proportion to thedegree of inclination of said ratio control levers. To decrease thespeed of the drivenvshaft with lr ect to the driving shaft, ratiocontrol levers 2 and the lattached rollers should, of course, beinclined in the direction opposite that described for increasing therelative speed of the drive shaft. f

During the spiraling ofthe intermediate idler rollers on the races thecontinuations of the axes of said rollers do not intersect the main axisofthe transmission-theaxis of driven shaft ,19-.but pass to one side orthe other according to whether ratio control levers have been inclinedin a direction to increase or decrease' output speed. It will be clearthat the axes of sald rollers must be restored to positions in whichcontinuations of said axes do intersect said main axis, before theforces acting on them thru the races will be in equilibrium so as tomaintain said rolli ers tracking in circular paths on the races.'l

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tllll lid tatiana l lwle-ile the rollers are tilting to vary speedratio. ly inspection ol ledig. Il, it will be seen that the obliquelaces on ratio control levers belonging to series of rollers l() inclinedownward :trom right to lett. llfhen, thereiore,

lever l2 has been inclined clockwise as described the axis ot a roller.40 controlled by it ii-'ill be moved so that its extension passes toone side ot the main axisf-tbr example, axis or roller il() shown insection in Fig. 3 iwould extend above it. New as the roller Mtilted-inthe sense indicated by the small arrows in llig. l-the anis will returnto the plane containing the roll center and main axis; the line ot theroller axis again intersects said main axis. rl`he oblique laces ofratio control levers lor rollers ll are inclined reversely ot thosepertaining to rollers d() since the drive from the driving race isopposite; but ot course the inclination is the same relative to sensesof movement.

rlhe lriction locking means adapts the main lever 31.02 to be locled inany position Within its range et' movement. Therefore changes ol speedratio may he made in theoretically inlinite gradations Within the rangeimposed by the machine design.

rllthough one particular embodiment oit the invention has been describedand illustrated it is not intended that the protection ntlorded shall belimited to the particulars disclosed, but that it shall be limited onlyby the appended claims. l

l claim:

l ln a friction transmission, a race having a torio racevvay, a trictionroller engaging the raceway, said roller having an axis ol rotationlying normally in aradial plane including the race axis and beinginclinable in a plane transverse ot the Arace axis and tree to tiltaround an axis tixed with respect to the axis ot' rotation ot the rollerand inclined vvith respect to a plane normal to the race airis.

2. a triction transmission, a race having a torio raceway, a frictionroller engaging the racevvay, said roller having an axis oil rotationlying normally in a radial plane including the race axis and beinginclinable in a plane transverse oil the race axis and `tree to tiltaround an axis hxed with respect to the axis ot rotation ol the rollerand with respect to a plane normal to the race axis in a plane normal tothe roller axis.

ll. :in a Afriction transmission, a race having a torio raceway, aroller engaging said racevvay, a roller supporting member including atrnnnion on which the roller is journaled, said trunnion beingadjustable in a plane substantially normal to the axis ot the' race,said roller being mounted to rotate on said trnnnion and means on saidtrunnion providing an axis inclined to a radial plane including theroller center and the axis oil the race around which the roller Ais treeto tilt in order to change the path ot Contact betvveen the roller andthe racevvay.

l. ln a friction transmission, a race having a torio raceway, a rollerengaging said racevvay, a roller positioning member, a trunnion elementconstituting a ratio control means pivoted to said positioning member onWhich the roller is mounted to rotate so as to swing in a planesubstantially normal to the axis of the race, and means on said trunnionproviding an axis around which the rollers are treeto tilt, said axisbeing inclined to a radial plane including the roller center and therace axis.

5. A friction transmission as delined in claim t in which the trunnionmember is provided vvith opposite faces at an angle to the radial planeincluding the roller center and the race axis and trunnion blocksadapted to rotate on said inclined faces.

6. A friction transmission as defined in claim l, in which the trunnionmember is provided with opposite flat laces inclined at an angle to theradial plane including the roller center and the race axis and trunnionblocks adapted to rotate on said inclined laces, said trunnion blocksbeing tree also to slide on said inclined laces toward and trom the axisot the race way.

7. A ilriction transmission as defined in claim l, in which the trunnionmember is provided with opposite dat parallel laces slightly inclined toa radial plane including the roller center and the race axis in a planenormal to said radial plane and parallel to the race axis and providedalso with particylindrical trunnion blocks having Hat laces, the datlaces of said trunnion blocks engag- 'ong the inclined faces of thetrunnion mem- 8.. ln a friction transmission, a race having a toric raceWay, a roller engaging said raceway, a roller positioning member, atrunnion mounted' thereon so as to be adjustable in a planesubstantially normal to the race axis, said trunnion includingparti-cylindrical trunnion blocks, a bearing ring on which the rollerrotates embracing said trunnion blocks, said trunnion and trunnionblocks having parallel engaging faces inclined slightly to said radialplane and said blocks and roller being free to tilt in the planes ofsaid laces..

9., lln a friction transmission, two races having opposed toricraceways, a lriction roller engaging said raceways, said roller beingtree to tilt around an axis fixed with respect to the axis ot rotationof the roller and inclined With respect to a plane normal to the raceaxis in a plane normal to the axis of rotation, of the roller in orderto change the paths oit Contact between the roller and the racewaysl fl0. lin a friction transmission, two races each having a torio racewayfacing the other,

lizo i' 25 tures.

an intermediate race having a toric race Way oneach face, frictionrollers interposed between said races, positioning means for saidrollers; means for inclining each of said rolli ers simultaneously in aplane transverse of the axis of said raceways, each of said rollersbeing free to tilt about an axis fixed with respect to the axis of theroller and inclined with respect to a plane normal to the race lo axisin aplane normal to the axis of rotatio of the roller. L 11. In afriction transmission, a race having a toric raceway, a roller engagingsaid raceway, an arm for positioning said roller, 15 a trunnion pivotedto said arm, said trunnion having two limbs embracing said arm andguided thereby, and means for guiding the tilting movement of the rollercomprist ing opposite parallel faces on said trunnion 20 inclined to aradial plane including the center of the roller and the race agis andtru'nnion blocks having parallel faces seated upon the inclined faces ofthe trunnion.

In? testimony whereof We aflx our signa- JAcoB. EHRLICH. JQHN o. ALMEN.

